An In Silico Study of PTH Amino Acids’ Adsorption Interactions with Amorphous Silica Surfaces
Paper ID : 1082-ICNS
Sara Aranifard *
Department of Chemical and Petroleum Engineering, Sharif University of Technology, Tehran, Iran
In thin layer chromatography, silica gel is applied on a plate as a stationary phase for variety of separations. The silica phase is an amorphous and porous form of silica with nanometer-scale voids and pores. After the sample has been applied on the plate, solvent is drawn up via capillary action. In the process, variety of intermolecular forces (between the solvent, solid, and solute) are in play. The aim of this preliminary study is to investigate the adsorption interaction between PTH derivatives of the twenty standard amino acids with three variations of amorphous silica surfaces (namely, untreated, with silanol groups, and with silanol and octylsilane groups) in vacuum in silico. Interestingly, it is revealed that our surface with both silanol and octylsilane groups has one deep void (unplanned and exacerbated due to bulky octylsilanes) which acted as a specific adsorption site for 18 out of 20 derivatives. Perhaps, if we had solvent in the system or higher coverage of hydrophobic groups, this specific site could be avoided and we could experience the effect of hydrophobicity of the surface in separation. Further, deprotonated glutamic and aspartic acids and protonated lysine and arginine could clearly be separated from all other neutral derivatives.
Amorphous Silica, Amino Acids, Thin Layer Chromatography, Monte Carlo Simulation, Simulated Annealing
Status : Abstract Accepted (Poster Presentation)